In general, a painting process in an automobile production line is to prevent corrosion of a vehicle body and increase merchantable quality by enhancing the beauty of a vehicle along with soundproofing.
In a painting line to which the painting process is applied, a paint film may be formed on the vehicle body by applying the following coats: an undercoat through electrodeposition, which is an important factor in anti-rusting and surface gloss of the vehicle body passing through a drying furnace in a pretreatment step; an intermediate coat for imparting chipping resistance, smoothness, weatherability, and the like of paint after application of a sealer; a top coat for glossy coating in view of the attractive exterior appearance of the vehicle; and a clearcoat.
The painting line is provided with a paint booth equipped with an air supply/exhaust device for smooth painting operation of the vehicle body in the step of applying the intermediate and top coats. The paint booth receives air of constant temperature and humidity through an air conditioning system.
The air conditioning system includes a burner section, a washer section, a cooling section, a heating section, a humidifying section, and the like. Outside air from which foreign materials have been removed through a filter may pass through each of the sections such that temperature and humidity are controlled, and thus the air of constant temperature and humidity required by the paint booth may be supplied to the paint booth. The air supplied to the paint booth is called “supply air.”
Such a conventional air conditioning system may consume excessive energy because it supplies the air of constant temperature and humidity to the paint booth, regardless of the temperature and humidity conditions of the outside air.